This invention relates to a process for the production of carbon molecular sieves having excellent oxygen adsorption properties.
Nitrogen is now widely used in a variety of industries and there is a great demand for an economical method of preparing nitrogen gas. Japanese Published Unexamined Patent Application No. 19595/1979 suggests a method in which molecular sieve coke materials are used for the separation of nitrogen from air. While this method per se is advantageous from economic point of view, the molecular sieve material employed fails to exhibit satisfactory oxygen adsorption properties. In U.S. Pat. No. 4,046,709 issued to one of the present inventors, there is disclosed a process for the production of a carbonaceous granular molecular sieve material from a vinylidene chloride copolymer. Although the molecular sieves produced by this prior art process have an excellent resistance to acids and a sufficient adsorption capacity, the oxygen adsorption properties of the material have been found to be unsatisfactory. Thus, the material cannot be advantageously applied to the concentration of nitrogen in air by selective adsorption of the oxygen.